In this edition of Agriculture Briefs, a study funded by the bio-tech industry finds gene-altered crops are helping American farmers grow more food and use less pesticides…and U.S. scientists say sunflowers could become a major source of domestic natural rubber.

A new study says American farmers are enjoying bigger harvests and spending less money on bug and weed-killing chemicals, because of their widespread adoption of genetically engineered crops. But critics suggest the new study is more wishful thinking than hard science.

The study, funded by the non-profit Rockefeller Foundation and the U.S. biotech giant, Monsanto, examined 40 varieties of gene-altered crops. These included the six plants, maize, soybeans, cotton, papaya, squash and canola, whose modified seeds are already widely planted in the United States. Study program director Leonard Giannessi told reporters that assuming all these biotech crops reach the marketplace, U.S. farmers will reap huge benefits.

"Our study concludes that food and fiber production in the United States will be 14 billion pounds [6.4 billion kilograms] greater as a result of the introduction of these forty biotech varieties. Farm income in the U.S., we predict, will go up $2.5 billion a year, as a result of adoption," he said. "An improvement of $2.5 billion in the farmer's bottom line is like giving the American farmer a five percent raise. That's what this technology does."

The study also projects that the 40 biotech crops, if adopted by U.S. farmers, would reduce chemical pesticide use by 74 million kilograms annually. And it concludes that in many instances, the biotech crops will provide farmers with their best, and sometimes only, means for controlling serious pest damage to the nation's food and fiber production.

But a prominent critic of gene-altered crops points out that more than half the engineered plant varieties described in the new study are still experimental, and many might never win government approval because of environmental or human health concerns. Charles Benbrook is a private consultant who once headed the National Academy of Science's Board on Agriculture. Mr. Benbrook said his own studies, based on actual production records, show that biotech crops, like herbicide-tolerant soybeans or insect-resistant maize, can be money-losing propositions for American farmers.

"The benefits of BT corn, engineered to control the European corn borer, are very much a function of the levels of pest pressure with this particular insect. In years when there are not very many of them across the Midwest, farmers don't even get back their investment in higher-priced seed corn," he said. "BT corn costs about 35-cents more per acre to buy the seed."

Still, as the new study points out, U.S. farmers continue to plant nearly two thirds of their soybean crop and half their maize with biotech varieties. Mr. Benbrook believes farmers use the engineered crops not to save money or to boost production, but as a simple way to manage bugs and weeds.

The lanky sunflower plant admired by gardeners and grown widely across the United States for its edible oil and seed, might soon become a latex and rubber factory for American industry. U.S. Department of Agriculture scientists are working to improve the leafy plant's natural latex content from a paltry one percent to around ten percent, tweaking it with laboratory-designed genes for latex production.

Karen Cornish, the lead researcher on the sunflower project, said that while a plant like the desert shrub, guayule, produces more natural latex than the sunflower, it can be grown only in America's desert southwest. The sunflower, by contrast, is grown in many states. However, farmers don't earn large profits from it and they could use a new and more lucrative market than cooking oil and seeds.

Researcher Karen Cornish believes that a latex-rich sunflower plant yielding commercial quantities of high-grade rubber would do more than provide American sunflower growers with extra income. Ms. Cornish said it would also break America's total dependence on foreign supplies of this strategic raw material. "You can't fly without natural rubber. Synthetic materials just don't do the job. There are over 40,000 things in a developed country made of natural rubber, and 400 medical devices, and we would really be up a gum tree, I suppose, if we didn't have it," she said. "So we want to reduce our dependence, and now with the homeland security issues, it becomes even more important to try to make rubber production in the United States…a reality."

Ms. Cornish said she is hopeful that a latex-rich sunflower plant can be ready for U.S. farmers within ten years.